Conventionally, as fine pattern processing techniques in LSI manufacturing, photolithography techniques have been used frequently. However, in photolithography techniques, there is a problem that it is difficult to perform processing on a pattern less than or equal to a wavelength of light used in exposure. As other fine pattern processing techniques, there are mask pattern lithography techniques (EB method) with electron beam lithography apparatuses. However, in the EB method, since a mask pattern is directly drawn using an electron beam, there is a problem that the drawing time increases as the drawing patterns increase, and that throughput up to pattern formation extremely decreases. Further, due to high-precision control of a mask position in an exposure apparatus for photolithography, increases in the size of the electron beam lithography apparatus in an exposure apparatus for the EB method, and the like, there is also a problem that using these methods makes the apparatus cost high.
As fine pattern (concavo-convex structure) processing techniques capable of solving the problems, the nanoimprint technique is known. The nanoimprint technique is a technique of pressing a mold with a fine concavo-convex structure formed against a resist film formed on a surface of a transfer-target substrate, and thereby transfering the fine concavo-convex structure formed on the mold to the surface of the transfer-target substrate (Patent Document 1). The mold used in the nanoimprint technique is obtained by processing a quartz substrate by a method such as the electron beam lithography method. In the nanoimprint technique, it is possible to form the fine structure of the nano-level repeatedly with ease once the mold is prepared, and it is thereby possible to actualize high throughput. Further, the technique eliminates the need of expensive apparatuses such as the exposure apparatus for photolithography and the EB exposure apparatus, and is economical. From such reasons, it has been considered application of the nanoimprint technique to various fields.
Further, by using the nanoimprint technique, proposed is a method of forming a fine concavo-convex structure made of an inorganic material on a surface of an inorganic substrate such as glass excellent in environmental resistance and weather resistance (Patent Document 1). In the method as described in Patent Document 1, for example, glass is heated to near the softening point, and is pressed against a die at a pressure of several-hundred N/cm2 or more in a vacuum, and the fine concavo-convex structure is thereby formed on the glass surface. However, such a method requires a die enduring high-temperature pressurization conditions and the nanoimprint process including the heat cool process. Therefore, a large facility is required, and such a problem occurs that the cycle time is long.
Therefore, proposed is a method of forming a ceramic fine-particle slurry layer on a substrate, pressing a mold to transfer a concavo-convex structure, and then, separating the mold (Patent Document 2, Patent Document 3). However, in this method, since the mold is pressed against the ceramic fine-particle slurry and baked, many asperities derived from fine particles are formed on the surface subjected to baking. Therefore, in the method, it is difficult to form a fine concavo-convex structure accurately reflecting the fine concavo-convex structure of the mold. Further, since it is necessary to use a rigid body such as a silicone mold as the mold, there is also the problem with uniform transfer characteristics to a larger area.
Further, proposed is a method of forming a layer of an inorganic hardened product on a surface of a fluorine-containing polymer mold having a fine concavo-convex structure, separating the mold from the inorganic hardened product in a hardening precursor state, then hardening the inorganic hardened product in the hardening precursor state, and obtaining the fine concavo-convex structure (Patent Document 4). However, in this method, since it is necessary to use a large amount of fluorine-containing resin that is expensive to enhance release properties between the inorganic hardened product and the mold, there is a problem of being poor in economy. Further, thermal transfer should be used in formation of the fine concavo-convex structure to the fluorine-containing polymer mold due to properties of the material, and large thermal shrinkage becomes a problem in transferring to a large area. Furthermore, transfer to the inorganic hardened product is of a batch type, and the method is also inferior in production efficiency.